Referential integrity
controls relationships between operations of an object
controls relationships between instances of a class
controls relationships between attributes in a table
controls relationships between tables in a database
Correct Answer :
D. controls relationships between tables in a database
Related Questions
What does the number of attributes in a relation is called?
Cardinality
Degree
Tuple
Order
Tape storage is referred to as
sequential access storage
direct access storage
random access storage
none of the above
A data manipulation command the combines the records from one or more tables is called
SELECT
PROJECT
JOIN
PRODUCT
.................. occurs due to velocity of propagation the frequency varies. Thus various frequency components of a signal arrive at the receiver at different times.
Noise
Delay distortion
Attenuation distortion
Dispersion
The physical location of a record is determined by a mathematical formula that transforms
a file key into a record location is :
B-Tree File
Hashed File
Indexed File
Sequential file.
A relation which is in 3NF is
in 1NF also
in 2NF also
free from transitive dependencies
All of these
In mesh topology, if the number of devices is n , then the number of ports present in each device is
n
n+1
n-1
n/2
FDDI protocol operates in
i) Transport layer
ii) Network layer
iii) Datalink layer
iv) Physical layer
i and ii only
ii and iii only
i and iii only
iii and iv only
A logical description of some portion of database that is required by a user to perform task is called as
System View
User View
Logical View
Data View
In two-phase locking
the data items are locked in growing phase.
the data items are released in shrinking phase.
Both A and B are true
Both A and B are false
In an E-R diagram attributes are represented by
rectangle.
square.
ellipse.
triangle.
The transaction consists of all statements executed between
the begin transaction and end transaction
the start transaction and end transaction
the begin transaction and finish transaction
none of the above.
The attribute that can be divided into other attributes is called
Simple Attribute
Composite Attribute
Multi-valued Attribute
Derived Attribute
The number of cursors depend on the
number of queries
number of attributes
size of memory area
none of these
What is the result of the following SQL statement ?
SELECT A.emp_Name, B.ph_num
FROM emp A LEFT OUTER JOIN phone B
ON A. emp_ID = B.emp_ID
A list of employees phone number
A list of all employees that have spouses, with phone number included in the list
A list of all employees names, including the phone number if they have one
Two lists : One list of employees, the other of phone numbers
Benefit of database normalization is
smaller number of tables
higher query processing efficiency
reduced I/O for most queries
reduced data redundancy
Which of the following extracts its data from the result of an SQL SELECT statement.
View
Synonym
Sequence
Transaction
Select the incorrect statement(s)
i) Shared locks are compatible with each other.
ii) A relation which is in 3NF may have redundancy due to composite keys.
iii) A table in a database can have multiple indexes.
i only
ii, only
ii, iii only
none of the above
Related fields in a database are grouped to form a
data file.
data record.
menu.
bank.
Authorization command in SQL
Allow
Access
Grant
none of the above
Thermal noise is often referred to as ............... noise, because it affects uniformly the different frequencies.
Gray
White
Blue
Black
Three SQL, DDL, CREATE commands are
Schema, Base and Table
Schema, Table and View
Base, Table and Schema
Key, Base and Table
Which of the following is also known as Offline storage ?
primary storage
secondary storage
tertiary storage
none of the above
Which of the following is the unit of signaling speed or modulation rate or the rate of symbol transmission?
Data rate
Bit rate
Signal to Noise Ratio
Baud rate
In defining the notion of the tuple variable, which one of the clause is useful?
as
by
from
none of the above
The ability to modify the conceptual schema without causing any change to the application program is known as
Physical data independence
Logical data independence
External data independence
Static data
Multivalued dependency is removed in
4 NF
3 NF
2 NF
1 NF
The race condition occurs when
Two concurrent processes attempt to interact with each other.
Two concurrent processes interact with different data files.
Two concurrent processes attempt to hold a data item .
none of the above.
Which of the following works as a filter?
UPDATE
DROP
ALTER
SELECT
The exists construct returns the value true, if the argument subquery is
empty
nonempty
contains null values
none of the above